Bright and early Saturday the building and electrical inspectors came to marvel at my tiny spectacle. Actually, I think the building inspectors exact comment was “looks like it won’t be any trouble adding a couple of rooms to it”. That comment and his signature is all that I needed to begin the next phase of construction.
The electrical inspector was happy with my wiring and signed off as well. The neatness of my wiring and having a set of wiring diagrams seemed to smooth out the process. He focused more on seeing that all the outlets were in the right places rather than the wiring itself.
The first step was to inspect every wall cavity for fasteners poking thru. These fasteners are exposed to the outside and can “sweat” during cold months. I cut them flush with a cut-off wheel and covered the stump with foam-in-a-can. At the same time I filled in any gaps and cracks that seemed to need it.
I cut blocks of rigid foam and stuffed them behing every outlet and switch box. Its tough to get fiberglass behind there and you typically end up with cold spots. The foam blocks prevent this from happening.
My walls will be filled with R19 fiberglass, and the ceiling will have R38. I am using unfaced insulation since the wall sheeting is air tight. My walls with “breathe” inward towards the living space. and you don’t want an air barrier trapping moisture.
The Right Tools
Having the right tools will help make your insulation job go a whole lot faster be more comfortable. Fiberglass insulation “sheds” little particles of fiberglass all over the place. These fibers are itchy if they get on your skin and are not that healthy to breathe.
Start with clothing. You want to cover up as much as you can. I dressed in a long sleeve shirt, gloves, hat, and shorts. Naturally, I wore a dust mask to keep from breathing in the fibers. If I had to do it again, I would have bought a Tyvek suit they sell for painting. I really hate fiberglass, but I’m too cheap to buy the alternatives.
For tools you need a good knife, a 4ft straight edge, and an 8ft straight edge. The straight edges can just be pieces of strapping. The knife can be any knife with a razor blade but honestly, typical utility or snap blade knives suck for insulation. Before this build I used them, but never again.
I found a knife call the Superkut made by Vintool. A long time ago in a galaxy far far away there was this guy named Vince who was an insulation contractor. Vince thought that all the knives for cutting insulation sucked so he made his own. It costs $25 and is sold at http://www.vintool.com or at Amazon. It kind looks home made but looks are deceiving.
The Vintool knife is the best 25 bucks I spent on this project! I was making factory looking cuts in a single pass thru R38 insulation. At one point during the day I left it downstairs and only had a utility knife on me and I needed to make a cut. It was this point when I realized how bad utility knives suck at cutting thru insulation. It’s a pretty specialized tool, but it’s not a ton of money, and it works really well.
Another tool you will want to manufacture is an outlet cutting template. Take a piece of scrap plywood about 10 inches wide by 18 inches tall. Cut a square notch out of it in the exact location of your outlet boxes. Make the notch about 1/2 inch smaller than the box. You simply line this template against the edges of the insulation, press down firmly, and cut the notch out.
I set up a piece of plywood as a work surface and made some marks corresponding to the lengths I would need to cut. The pro’s cut insulation up on the spot against the wall…I am not a pro and prefer to measure and cut as needed.
The process I used was to cut a piece to the height of my wall plus one inch. If it needed to be trimmed lengthwise I added an inch to the actual width and used an 8ft length of strapping as a straight edge to trim the sheet.
It seems fairly easy to “hide” 1 to 1.5 inches in the bay without having it bunch up on you. You want the bay completely filled without bunching up as this decreases the R value.
When you encounter wires, you simply split the insulation and place half of the insulation behind and half in front. Switch boxes I used the vintool to cut them out on the spot. You just sort of compress the insulation and feel for the box edges and make some slices.
Saturday I was able to install all 6 rolls on the walls by days end. Sunday I went to the building center and picked up 6 packages of R38 for the ceiling and had them installed well before the day ended. All totalled, I would estimate the insulation took about 10 hours to install.
After work this week I will install sheetrock around the windows and doors. I also have some last-minute wires to run for the phone, speakers, etc. Next weekend, Tim and I will begin hanging sheetrock after the building inspector comes by to sign off on my insulation.